Technical Field
Embodiments described herein relate to the field of graphical information processing and more particularly, to efficiently generating blurred effects on a display.
Description of the Related Art
Part of the operation of many computer systems, including portable digital devices such as mobile phones, notebook computers, and the like, is to display images on a display device. Accordingly, these systems typically incorporate functionality for generating images and data, including video information, which are subsequently output to the display device. Such devices typically include a graphics processing unit (GPU), video graphics circuitry (i.e., a display pipeline), and/or other logic to process images and video information for subsequent display.
Typically, the smallest item of image information in digital imaging is called a “picture element”—more generally referred to as a “pixel.” For convenience, pixels are generally arranged in a regular two-dimensional grid. By using such an arrangement, many common operations can be implemented by uniformly applying the same operation to each pixel independently. Since each pixel is an elemental part of a digital image, a greater number of pixels can provide a more accurate representation of the digital image. To represent a specific color on an electronic display, each pixel may have multiple values corresponding to each of the colors red, green, and blue. By combining these colors in various ways, a wide variety of colors in the visible spectrum (that portion of the electromagnetic spectrum visible to the human eye) may be generated. Some formats for electronic displays may also include a fourth value, called alpha, which represents the transparency of the pixel. This format is commonly referred to as ARGB or RGBA. Another format for representing pixel color is YCbCr, where Y corresponds to the luma, or brightness, of a pixel and Cb and Cr correspond to two color-difference chrominance components, representing the blue-difference (Cb) and red-difference (Cr).
Frequently, image and video information displayed on display devices such as liquid crystal display (LCD) and light emitting diode (LED) displays is interpreted as a succession of ordered image frames, or “frames” for short. While generally a frame is one of the many still images that make up a complete moving picture or video stream, a frame can also be interpreted more broadly as simply a still image displayed on a digital (discrete or progressive scan) display. A frame typically consists of a specified number of pixels according to the resolution of the image/video frame. Most graphics systems use memories (commonly referred to as “frame buffers”) to store pixels for image and video frame information. The information in a frame buffer typically includes color values for every pixel to be displayed on the screen.
Processing the source image data in the source frames can consume large amounts of power when generating various special effects desired in many videos, games, and images being displayed on modern computing systems. For portable digital devices employing a display device, it is challenging to generate these special effects on the display device while at the same time minimizing power consumption so as to maximize the battery life of the portable device.